Trait TraceContextExt

pub trait TraceContextExt {
    // Required methods
    fn current_with_span<T: Span + Send + Sync + 'static>(span: T) -> Self;
    fn with_span<T: Span + Send + Sync + 'static>(&self, span: T) -> Self;
    fn span(&self) -> SpanRef<'_>;
    fn has_active_span(&self) -> bool;
    fn with_remote_span_context(&self, span_context: SpanContext) -> Self;
}

Methods for storing and retrieving trace data in a Context.

See Context for examples of setting and retrieving the current context.

Required Methods

fn current_with_span<T: Span + Send + Sync + 'static>(span: T) -> Self

Returns a clone of the current context with the included Span.

Examples

use opentelemetry::{global, trace::{TraceContextExt, Tracer}, Context};

let tracer = global::tracer("example");

// build a span
let span = tracer.start("parent_span");

// create a new context from the currently active context that includes this span
let cx = Context::current_with_span(span);

// create a child span by explicitly specifying the parent context
let child = tracer.start_with_context("child_span", &cx);

fn with_span<T: Span + Send + Sync + 'static>(&self, span: T) -> Self

Returns a clone of this context with the included span.

Examples

use opentelemetry::{global, trace::{TraceContextExt, Tracer}, Context};

fn fn_with_passed_in_context(cx: &Context) {
    let tracer = global::tracer("example");

    // build a span
    let span = tracer.start("parent_span");

    // create a new context from the given context that includes the span
    let cx_with_parent = cx.with_span(span);

    // create a child span by explicitly specifying the parent context
    let child = tracer.start_with_context("child_span", &cx_with_parent);
}

fn span(&self) -> SpanRef<'_>

Returns a reference to this context’s span, or the default no-op span if none has been set.

Examples

use opentelemetry::{trace::TraceContextExt, Context};

// Add an event to the currently active span
Context::map_current(|cx| cx.span().add_event("An event!", vec![]));

fn has_active_span(&self) -> bool

Returns whether or not an active span has been set.

Examples

use opentelemetry::{trace::TraceContextExt, Context};

assert!(!Context::map_current(|cx| cx.has_active_span()));

fn with_remote_span_context(&self, span_context: SpanContext) -> Self

Returns a copy of this context with the span context included.

This is useful for building propagators.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl TraceContextExt for Context